Susceptibility of the soft tick <i>Ornithodoros savignyi</i> to different classes of acaricides

Abstract

The susceptibility of Ornithodorus savignyi to here classes of acaricides namely Dieldrin (organochlorines), coumaphos and Diazinon (Organophosphates) and Cypermehrin (Pyrehroid) were tested using he shaw larval packet test adapted by he FAO. Tick mortality was observed to increase proportionately with increasing concentration of acaricides. Cypermethrin elicited 82.5% and 100% mortality at a discriminating concentration of 0.05% and 0.1% respectively. A mortality of 100% was recorded in batches exposed to 0.2% Diazinon and 0.8% Coumaphos and Dieldrin. Least mortality rate of 12% was observed in ticks exposed to 0.1% Coumphos. The study further confirms the development of resistance by ticks to Coumaphos. It also observed Cypermethrin to be an effective and promising acaricide against Ornihodoros savignyi and is application may delay he appearance of resistance to other classes of acaricides.

The Nigerian Journal of Parasitology Vol. 24 2003: 179-184